Granny postmortemAs with any experiment, it's probably a good idea to reflect on the methodology in practice before drawing any quick conclusions about the results.

What we found was that a day was probably too aggressive. Some folks took closer to two days to deliver Granny in their respective language by the time all was said and done. Most delays were simply hitting a "snag" like a typo in a connection string parameter.

Having different people work on each language probably skews the results in terms of gauging which language would provide the "easiest" transition. Was Ruby done really quickly (matter of hours) because Brian is fast or because Rails generates most of the scaffolding for you?

Of course, people learn at different paces and have different skills. Still, it was really neat to watch this come together. I hope to follow up in the near future with more highlights on each language, especially some of the less mature ones.

Are the transition costs between two languages as difficult for a developer as people make them out to be? No. For new projects, knowing that the transition costs between two high-level languages aren't really that high might make it an easier sell to your management. Of course, "It's Monday so let's rewrite everything in Erlang" will make you seem like a Hipster Hacker at best and a clown at worst. That said, maybe your boss is open to allowing the next project be built in Ruby or Scala because you promise to at least learn the basics in a day.